Dear Wise/Experienced Diesel Persons,

I usually hang out in the 1/2A forum so I don't "know" any of you but I am hoping that you will accept me into you warm embrace.

I have three Diesel engines - all PAWs. Generally speaking I love 'em except for two things. . .

Thing one. Fuel proofing. Usually I use laminating film with Rustoleum paint to cover open structures. Glow fuel is not a problem but the diesel goo seems to penetrate everywhere. Any recommendations on the best Iron-on for diesel useage?

Thing two. Solid balsa finishing. One of my planned Winter projects is an all-sheet, Eric Clutton design, "Tadpole" (thanks Gray) for RO function. For glow-powered fuel proofing I like multi-coats of Water-Based Polyurethane (then floral spray decoration colors usually) finally Butyrate dope. I would like to just use the WBP for the "Tadpole" if I could get away with it to keepit light. Has anyone had good luck with just using WBP or even "real" Polyurethane?

Thanks.

I use Hobby Poxy 2 part epoxy paint on the motor area and other exposed wood parts that might get oil or fuel. I mix up a small amount stir well and let it set 45 minutes. Mix again before use add thinner if needed and paint with a brush. Cover remaining paint in the small containe you mixed it in with plastic wrap secured with a rubber band and place in the refrigerator. Let the painted surface dry for 24 hours and lightly sand before adding a second coat. Allow the paint to warm up to room temp after removing from the fridg before adding the next coat. 2 coats is all you normally need, 3 max. Very durable finish and adds strength to the structure. Hobby Poxy is no longer available and the stock I have is from the late 1970's and 1980's and still works. There is a new 2 part epoxy paint just recently on the market for model use. For covering I use MonoKote with no problem with diesel fuel. Before MonoKote and Hobby Poxy it was silk/silkspan and dope.

Welcome to the diesel forum Raymond, although I am relatively new to the forum myself. Can you tell us about the all-sheet, Eric Clutton designed, "Tadpole". Do you have a photo of this model and / or the plan? What size engine does it take, what is it's wingspan? THANKS Much.

Ray,

Water based Polyurethane made by "Flecto" is absolutely diesel proof. I use it exclusively on my models.


Francis

Thanks for your replies, oh wise and generous (but perhaps smelly to the rest of the world) gentlemen,

I am SO happy to hear that I can use WBP for wood! It makes the decision of when to start on the Tadpole muche easier. I didn't really want to contend with two-part 'poxies or frankly anything I didn't already have on hand.

The other, slight, possibility I had considered was tissue and dope. When I first read about the technique, I tried a sample of tissue over laminating film on a piece of damaged tail section I happened to have. Yes it added some weight but not as much as I had feared. I filed that away for a future old-time electric I've been pondering. But it could have an application for a diesel too I expect.

The Tadpole is a Clutton design from a British magazine - don't know which one and don't know when it was published (wish I did so I could fly it at next Summer's Old Timer events). Its all-sheet Tailless, Rudder-only design. The wing is about 36-inches, swept back, tapered, has reflexed-fixed ailerons, and uses two sheets of LIGHT 1/4-inch balsa. The fuselage is conventional about 24-inches long with a single fin and moveable rudder.

The plans show a Citizenship compound escapement twisting the yoke and level of the rudder. I would be tempted to use the same mechanism - servo actuated.

The text calls for a TD .020 (one of my favorite engines) but I was thinking of my PAW .033 with throttle so I could kinda cheap to gain some height and speed comtrol.

It is described as, "fast glide, needs a hefty launch, is low drag, and low lift." I would expect it to be pretty fast at full throttle but never having mastered RO on my first (and only for many years) R/C model 48 years ago I feel the urge to "exonerate" myself - and find a new/different home for the .033.

If anyone is interested it would be easy to copy the three pages it takes for the text and plan. So how 'bout a PM with your mail address?

If you go over to the control line forum and find Tony Elmore's website this may help. I think he shows the Tadpole article. Even better, contact Eric Clutton and ask him. His email can be found on this forum if you cruse around.

Just a comment. no way will a paw .033 ever approach the performance of a TD.020 or the weight advantage of the TD -- They are worlds apart and if the tadpole is marginal and requires a healthy launch then the TD is the way to go. You do have some things on your side however and the recent improvements in servos and batteries will allow you to cut some serious weight from your project. I use 120 ma packs custom made from Nimh cells (1/3 AAA's) and 4gm servos for my .010 and .020 projects and have much success with these. I have a 4 channel piper cub with TD .010 power that weighs 4 oz and flys great. I have to recharge the pack after 2 flights but that only takes a few seconds and I'm back in the air.

Jim,

Thanks for the pointer to Tony Elmore's site! Love those old British designs. But Tadpole is supposed to have a radio in it.

Just for old times sake, another plane on my build-this-winter list is White Heat. Its an R/C combat model from a 70s or 80s RCM&E (I think) full-size plan that I'd like to put my PAW 2.5 in.

Gary,

TD .010s and .020s are among my favorite engines. But I was really looking for a home for that little diesel. However, if the .033 is not enough I could always try my .049. When I read the recommendation for a healthy launch I thought it meant that it flew faster than your average model because of the reduced drag of the flying-wing configuration. I guess I'll just have to try it to find out.

As for contacting Eric, I did when I was searching for Sharkface plans. His reply was very gracious but he said that he hadn't kept much of his stuff from his "early days". I talked to him for a little while at Toledo last year. Bought an engine and some fuel too. Neat guy.